/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.solr.search;

import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.solr.common.params.CommonParams;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.StrUtils;
import org.apache.solr.request.SolrQueryRequest;

import java.util.List;

/**
 * Parse Solr's variant on the Lucene QueryParser syntax. <br>
 * Other parameters:
 * <ul>
 * <li>q.op - the default operator "OR" or "AND"</li>
 * <li>df - the default field name</li>
 * </ul>
 * <br>
 * Example:
 * <code>{!lucene q.op=AND df=text sort='price asc'}myfield:foo +bar -baz</code>
 */
public class LuceneQParserPlugin extends QParserPlugin {
	public static String NAME = "lucene";

	public void init(NamedList args) {
	}

	@Override
	public QParser createParser(String qstr, SolrParams localParams,
			SolrParams params, SolrQueryRequest req) {
		return new LuceneQParser(qstr, localParams, params, req);
	}
}

class LuceneQParser extends QParser {
	SolrQueryParser lparser;

	public LuceneQParser(String qstr, SolrParams localParams,
			SolrParams params, SolrQueryRequest req) {
		super(qstr, localParams, params, req);
	}

	@Override
	public Query parse() throws ParseException {
		String qstr = getString();
		if (qstr == null || qstr.length() == 0)
			return null;

		String defaultField = getParam(CommonParams.DF);
		if (defaultField == null) {
			defaultField = getReq().getSchema().getDefaultSearchFieldName();
		}
		lparser = new SolrQueryParser(this, defaultField);

		// these could either be checked & set here, or in the SolrQueryParser
		// constructor
		String opParam = getParam(QueryParsing.OP);
		if (opParam != null) {
			lparser.setDefaultOperator("AND".equals(opParam) ? QueryParser.Operator.AND
					: QueryParser.Operator.OR);
		} else {
			// try to get default operator from schema
			QueryParser.Operator operator = getReq().getSchema()
					.getSolrQueryParser(null).getDefaultOperator();
			lparser.setDefaultOperator(null == operator ? QueryParser.Operator.OR
					: operator);
		}

		return lparser.parse(qstr);
	}

	@Override
	public String[] getDefaultHighlightFields() {
		return lparser == null ? new String[] {} : new String[] { lparser
				.getField() };
	}

}

class OldLuceneQParser extends LuceneQParser {
	String sortStr;

	public OldLuceneQParser(String qstr, SolrParams localParams,
			SolrParams params, SolrQueryRequest req) {
		super(qstr, localParams, params, req);
	}

	@Override
	public Query parse() throws ParseException {
		// handle legacy "query;sort" syntax
		if (getLocalParams() == null) {
			String qstr = getString();
			if (qstr == null || qstr.length() == 0)
				return null;
			sortStr = getParams().get(CommonParams.SORT);
			if (sortStr == null) {
				// sort may be legacy form, included in the query string
				List<String> commands = StrUtils.splitSmart(qstr, ';');
				if (commands.size() == 2) {
					qstr = commands.get(0);
					sortStr = commands.get(1);
				} else if (commands.size() == 1) {
					// This is need to support the case where someone sends:
					// "q=query;"
					qstr = commands.get(0);
				} else if (commands.size() > 2) {
					throw new ParseException(
							"If you want to use multiple ';' in the query, use the 'sort' param.");
				}
			}
			setString(qstr);
		}

		return super.parse();
	}

	@Override
	public SortSpec getSort(boolean useGlobal) throws ParseException {
		SortSpec sort = super.getSort(useGlobal);
		if (sortStr != null && sortStr.length() > 0 && sort.getSort() == null) {
			Sort oldSort = QueryParsing.parseSort(sortStr, getReq());
			if (oldSort != null) {
				sort.sort = oldSort;
			}
		}
		return sort;
	}

}
